The Statistical Core has overall responsibility for the quality of the data and the statistical analyses for the Einstein Aging Study program project. Specific aims of the Statistical Core are: (1) To ensure high quality, accessible data for each of the projects and Cores; (2) To assist investigators in the analyses of their data on both a collaborative and consultative basis; (3) To facilitate the exchange of data and ideas among projects and cores; (4) To assist investigators in framing testable hypotheses, formulating questions in a manner conducive to statistical estimation, and in generating hypotheses involving data from multiple projects; (5) To assist project investigators in conducting ,hypothesis testing using both cross-sectional and longitudinal data as appropriate; (6) To develop methods to idistinguish neuropsychological, neurologic, and neuropathologic deficits exhibited in early AD from changes that occur in normal aging; and (7) to develop new statistical methodology, and to innovatively apply existing methodology, to problems where such development is needed to address the other aims of this core and the projects.